1388 lines
58 KiB
Rust
1388 lines
58 KiB
Rust
//! Methods for lowering the HIR to types. There are two main cases here:
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//!
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//! - Lowering a type reference like `&usize` or `Option<foo::bar::Baz>` to a
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//! type: The entry point for this is `Ty::from_hir`.
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//! - Building the type for an item: This happens through the `type_for_def` query.
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//!
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//! This usually involves resolving names, collecting generic arguments etc.
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use std::cell::{Cell, RefCell};
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use std::{iter, sync::Arc};
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use base_db::CrateId;
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use chalk_ir::{cast::Cast, fold::Shift, interner::HasInterner, Mutability, Safety};
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use hir_def::intern::Interned;
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use hir_def::{
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adt::StructKind,
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body::{Expander, LowerCtx},
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builtin_type::BuiltinType,
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generics::{TypeParamProvenance, WherePredicate, WherePredicateTypeTarget},
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path::{GenericArg, Path, PathSegment, PathSegments},
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resolver::{HasResolver, Resolver, TypeNs},
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type_ref::{TraitRef as HirTraitRef, TypeBound, TypeRef},
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AdtId, AssocContainerId, AssocItemId, ConstId, ConstParamId, EnumId, EnumVariantId, FunctionId,
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GenericDefId, HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId,
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TypeAliasId, TypeParamId, UnionId, VariantId,
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};
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use hir_expand::{name::Name, ExpandResult};
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use la_arena::ArenaMap;
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use smallvec::SmallVec;
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use stdx::impl_from;
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use syntax::ast;
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use crate::{
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consteval,
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db::HirDatabase,
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mapping::ToChalk,
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static_lifetime, to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
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utils::{
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all_super_trait_refs, associated_type_by_name_including_super_traits, generics, Generics,
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},
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AliasEq, AliasTy, Binders, BoundVar, CallableSig, DebruijnIndex, DynTy, FnPointer, FnSig,
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FnSubst, ImplTraitId, Interner, OpaqueTy, PolyFnSig, ProjectionTy, QuantifiedWhereClause,
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QuantifiedWhereClauses, ReturnTypeImplTrait, ReturnTypeImplTraits, Substitution,
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TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyKind, WhereClause,
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};
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#[derive(Debug)]
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pub struct TyLoweringContext<'a> {
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pub db: &'a dyn HirDatabase,
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pub resolver: &'a Resolver,
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in_binders: DebruijnIndex,
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/// Note: Conceptually, it's thinkable that we could be in a location where
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/// some type params should be represented as placeholders, and others
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/// should be converted to variables. I think in practice, this isn't
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/// possible currently, so this should be fine for now.
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pub type_param_mode: TypeParamLoweringMode,
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pub impl_trait_mode: ImplTraitLoweringMode,
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impl_trait_counter: Cell<u16>,
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/// When turning `impl Trait` into opaque types, we have to collect the
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/// bounds at the same time to get the IDs correct (without becoming too
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/// complicated). I don't like using interior mutability (as for the
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/// counter), but I've tried and failed to make the lifetimes work for
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/// passing around a `&mut TyLoweringContext`. The core problem is that
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/// we're grouping the mutable data (the counter and this field) together
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/// with the immutable context (the references to the DB and resolver).
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/// Splitting this up would be a possible fix.
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opaque_type_data: RefCell<Vec<ReturnTypeImplTrait>>,
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expander: RefCell<Option<Expander>>,
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}
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impl<'a> TyLoweringContext<'a> {
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pub fn new(db: &'a dyn HirDatabase, resolver: &'a Resolver) -> Self {
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let impl_trait_counter = Cell::new(0);
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let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
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let type_param_mode = TypeParamLoweringMode::Placeholder;
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let in_binders = DebruijnIndex::INNERMOST;
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let opaque_type_data = RefCell::new(Vec::new());
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Self {
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db,
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resolver,
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in_binders,
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impl_trait_mode,
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impl_trait_counter,
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type_param_mode,
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opaque_type_data,
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expander: RefCell::new(None),
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}
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}
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pub fn with_debruijn<T>(
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&self,
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debruijn: DebruijnIndex,
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f: impl FnOnce(&TyLoweringContext) -> T,
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) -> T {
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let opaque_ty_data_vec = self.opaque_type_data.replace(Vec::new());
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let expander = self.expander.replace(None);
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let new_ctx = Self {
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in_binders: debruijn,
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impl_trait_counter: Cell::new(self.impl_trait_counter.get()),
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opaque_type_data: RefCell::new(opaque_ty_data_vec),
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expander: RefCell::new(expander),
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..*self
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};
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let result = f(&new_ctx);
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self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
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self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
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self.expander.replace(new_ctx.expander.into_inner());
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result
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}
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pub fn with_shifted_in<T>(
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&self,
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debruijn: DebruijnIndex,
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f: impl FnOnce(&TyLoweringContext) -> T,
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) -> T {
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self.with_debruijn(self.in_binders.shifted_in_from(debruijn), f)
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}
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pub fn with_impl_trait_mode(self, impl_trait_mode: ImplTraitLoweringMode) -> Self {
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Self { impl_trait_mode, ..self }
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}
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pub fn with_type_param_mode(self, type_param_mode: TypeParamLoweringMode) -> Self {
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Self { type_param_mode, ..self }
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}
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}
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#[derive(Copy, Clone, Debug, PartialEq, Eq)]
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pub enum ImplTraitLoweringMode {
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/// `impl Trait` gets lowered into an opaque type that doesn't unify with
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/// anything except itself. This is used in places where values flow 'out',
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/// i.e. for arguments of the function we're currently checking, and return
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/// types of functions we're calling.
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Opaque,
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/// `impl Trait` gets lowered into a type variable. Used for argument
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/// position impl Trait when inside the respective function, since it allows
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/// us to support that without Chalk.
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Param,
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/// `impl Trait` gets lowered into a variable that can unify with some
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/// type. This is used in places where values flow 'in', i.e. for arguments
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/// of functions we're calling, and the return type of the function we're
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/// currently checking.
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Variable,
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/// `impl Trait` is disallowed and will be an error.
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Disallowed,
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}
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#[derive(Copy, Clone, Debug, PartialEq, Eq)]
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pub enum TypeParamLoweringMode {
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Placeholder,
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Variable,
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}
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impl<'a> TyLoweringContext<'a> {
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pub fn lower_ty(&self, type_ref: &TypeRef) -> Ty {
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self.lower_ty_ext(type_ref).0
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}
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pub fn lower_ty_ext(&self, type_ref: &TypeRef) -> (Ty, Option<TypeNs>) {
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let mut res = None;
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let ty = match type_ref {
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TypeRef::Never => TyKind::Never.intern(&Interner),
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TypeRef::Tuple(inner) => {
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let inner_tys = inner.iter().map(|tr| self.lower_ty(tr));
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TyKind::Tuple(inner_tys.len(), Substitution::from_iter(&Interner, inner_tys))
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.intern(&Interner)
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}
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TypeRef::Path(path) => {
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let (ty, res_) = self.lower_path(path);
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res = res_;
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ty
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}
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TypeRef::RawPtr(inner, mutability) => {
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let inner_ty = self.lower_ty(inner);
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TyKind::Raw(lower_to_chalk_mutability(*mutability), inner_ty).intern(&Interner)
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}
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TypeRef::Array(inner, len) => {
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let inner_ty = self.lower_ty(inner);
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let const_len = consteval::usize_const(len.as_usize());
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TyKind::Array(inner_ty, const_len).intern(&Interner)
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}
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TypeRef::Slice(inner) => {
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let inner_ty = self.lower_ty(inner);
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TyKind::Slice(inner_ty).intern(&Interner)
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}
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TypeRef::Reference(inner, _, mutability) => {
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let inner_ty = self.lower_ty(inner);
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let lifetime = static_lifetime();
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TyKind::Ref(lower_to_chalk_mutability(*mutability), lifetime, inner_ty)
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.intern(&Interner)
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}
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TypeRef::Placeholder => TyKind::Error.intern(&Interner),
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TypeRef::Fn(params, is_varargs) => {
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let substs = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
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Substitution::from_iter(&Interner, params.iter().map(|tr| ctx.lower_ty(tr)))
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});
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TyKind::Function(FnPointer {
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num_binders: 0, // FIXME lower `for<'a> fn()` correctly
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sig: FnSig { abi: (), safety: Safety::Safe, variadic: *is_varargs },
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substitution: FnSubst(substs),
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})
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.intern(&Interner)
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}
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TypeRef::DynTrait(bounds) => {
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let self_ty =
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TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(&Interner);
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let bounds = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
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QuantifiedWhereClauses::from_iter(
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&Interner,
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bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)),
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)
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});
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let bounds = crate::make_only_type_binders(1, bounds);
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TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(&Interner)
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}
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TypeRef::ImplTrait(bounds) => {
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match self.impl_trait_mode {
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ImplTraitLoweringMode::Opaque => {
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let idx = self.impl_trait_counter.get();
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self.impl_trait_counter.set(idx + 1);
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assert!(idx as usize == self.opaque_type_data.borrow().len());
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// this dance is to make sure the data is in the right
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// place even if we encounter more opaque types while
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// lowering the bounds
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self.opaque_type_data.borrow_mut().push(ReturnTypeImplTrait {
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bounds: crate::make_only_type_binders(1, Vec::new()),
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});
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// We don't want to lower the bounds inside the binders
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// we're currently in, because they don't end up inside
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// those binders. E.g. when we have `impl Trait<impl
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// OtherTrait<T>>`, the `impl OtherTrait<T>` can't refer
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// to the self parameter from `impl Trait`, and the
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// bounds aren't actually stored nested within each
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// other, but separately. So if the `T` refers to a type
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// parameter of the outer function, it's just one binder
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// away instead of two.
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let actual_opaque_type_data = self
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.with_debruijn(DebruijnIndex::INNERMOST, |ctx| {
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ctx.lower_impl_trait(&bounds)
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});
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self.opaque_type_data.borrow_mut()[idx as usize] = actual_opaque_type_data;
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let func = match self.resolver.generic_def() {
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Some(GenericDefId::FunctionId(f)) => f,
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_ => panic!("opaque impl trait lowering in non-function"),
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};
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let impl_trait_id = ImplTraitId::ReturnTypeImplTrait(func, idx);
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let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into();
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let generics = generics(self.db.upcast(), func.into());
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let parameters = generics.bound_vars_subst(self.in_binders);
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TyKind::Alias(AliasTy::Opaque(OpaqueTy {
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opaque_ty_id,
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substitution: parameters,
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}))
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.intern(&Interner)
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}
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ImplTraitLoweringMode::Param => {
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let idx = self.impl_trait_counter.get();
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// FIXME we're probably doing something wrong here
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self.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
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if let Some(def) = self.resolver.generic_def() {
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let generics = generics(self.db.upcast(), def);
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let param = generics
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.iter()
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.filter(|(_, data)| {
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data.provenance == TypeParamProvenance::ArgumentImplTrait
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})
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.nth(idx as usize)
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.map_or(TyKind::Error, |(id, _)| {
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TyKind::Placeholder(to_placeholder_idx(self.db, id))
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});
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param.intern(&Interner)
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} else {
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TyKind::Error.intern(&Interner)
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}
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}
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ImplTraitLoweringMode::Variable => {
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let idx = self.impl_trait_counter.get();
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// FIXME we're probably doing something wrong here
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self.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
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let (parent_params, self_params, list_params, _impl_trait_params) =
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if let Some(def) = self.resolver.generic_def() {
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let generics = generics(self.db.upcast(), def);
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generics.provenance_split()
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} else {
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(0, 0, 0, 0)
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};
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TyKind::BoundVar(BoundVar::new(
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self.in_binders,
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idx as usize + parent_params + self_params + list_params,
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))
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.intern(&Interner)
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}
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ImplTraitLoweringMode::Disallowed => {
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// FIXME: report error
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TyKind::Error.intern(&Interner)
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}
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}
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}
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TypeRef::Macro(macro_call) => {
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let (expander, recursion_start) = {
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let mut expander = self.expander.borrow_mut();
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if expander.is_some() {
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(Some(expander), false)
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} else {
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if let Some(module_id) = self.resolver.module() {
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*expander = Some(Expander::new(
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self.db.upcast(),
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macro_call.file_id,
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module_id,
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));
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(Some(expander), true)
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} else {
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(None, false)
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}
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}
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};
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let ty = if let Some(mut expander) = expander {
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let expander_mut = expander.as_mut().unwrap();
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let macro_call = macro_call.to_node(self.db.upcast());
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match expander_mut.enter_expand::<ast::Type>(self.db.upcast(), macro_call) {
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Ok(ExpandResult { value: Some((mark, expanded)), .. }) => {
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let ctx =
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LowerCtx::new(self.db.upcast(), expander_mut.current_file_id());
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let type_ref = TypeRef::from_ast(&ctx, expanded);
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drop(expander);
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let ty = self.lower_ty(&type_ref);
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self.expander
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.borrow_mut()
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.as_mut()
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.unwrap()
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.exit(self.db.upcast(), mark);
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Some(ty)
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}
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_ => None,
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}
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} else {
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None
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};
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if recursion_start {
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*self.expander.borrow_mut() = None;
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}
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ty.unwrap_or_else(|| TyKind::Error.intern(&Interner))
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}
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TypeRef::Error => TyKind::Error.intern(&Interner),
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};
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(ty, res)
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}
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/// This is only for `generic_predicates_for_param`, where we can't just
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/// lower the self types of the predicates since that could lead to cycles.
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/// So we just check here if the `type_ref` resolves to a generic param, and which.
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fn lower_ty_only_param(&self, type_ref: &TypeRef) -> Option<TypeParamId> {
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let path = match type_ref {
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TypeRef::Path(path) => path,
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_ => return None,
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};
|
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if path.type_anchor().is_some() {
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return None;
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}
|
|
if path.segments().len() > 1 {
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return None;
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}
|
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let resolution =
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match self.resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
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Some((it, None)) => it,
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_ => return None,
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};
|
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if let TypeNs::GenericParam(param_id) = resolution {
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Some(param_id)
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} else {
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None
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}
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}
|
|
|
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pub(crate) fn lower_ty_relative_path(
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&self,
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ty: Ty,
|
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// We need the original resolution to lower `Self::AssocTy` correctly
|
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res: Option<TypeNs>,
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remaining_segments: PathSegments<'_>,
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) -> (Ty, Option<TypeNs>) {
|
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if remaining_segments.len() == 1 {
|
|
// resolve unselected assoc types
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let segment = remaining_segments.first().unwrap();
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(self.select_associated_type(res, segment), None)
|
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} else if remaining_segments.len() > 1 {
|
|
// FIXME report error (ambiguous associated type)
|
|
(TyKind::Error.intern(&Interner), None)
|
|
} else {
|
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(ty, res)
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|
}
|
|
}
|
|
|
|
pub(crate) fn lower_partly_resolved_path(
|
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&self,
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|
resolution: TypeNs,
|
|
resolved_segment: PathSegment<'_>,
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|
remaining_segments: PathSegments<'_>,
|
|
infer_args: bool,
|
|
) -> (Ty, Option<TypeNs>) {
|
|
let ty = match resolution {
|
|
TypeNs::TraitId(trait_) => {
|
|
// if this is a bare dyn Trait, we'll directly put the required ^0 for the self type in there
|
|
let self_ty = if remaining_segments.len() == 0 {
|
|
Some(
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0))
|
|
.intern(&Interner),
|
|
)
|
|
} else {
|
|
None
|
|
};
|
|
let trait_ref =
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self.lower_trait_ref_from_resolved_path(trait_, resolved_segment, self_ty);
|
|
let ty = if remaining_segments.len() == 1 {
|
|
let segment = remaining_segments.first().unwrap();
|
|
let found = self
|
|
.db
|
|
.trait_data(trait_ref.hir_trait_id())
|
|
.associated_type_by_name(&segment.name);
|
|
match found {
|
|
Some(associated_ty) => {
|
|
// FIXME handle type parameters on the segment
|
|
TyKind::Alias(AliasTy::Projection(ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: trait_ref.substitution,
|
|
}))
|
|
.intern(&Interner)
|
|
}
|
|
None => {
|
|
// FIXME: report error (associated type not found)
|
|
TyKind::Error.intern(&Interner)
|
|
}
|
|
}
|
|
} else if remaining_segments.len() > 1 {
|
|
// FIXME report error (ambiguous associated type)
|
|
TyKind::Error.intern(&Interner)
|
|
} else {
|
|
let dyn_ty = DynTy {
|
|
bounds: crate::make_only_type_binders(
|
|
1,
|
|
QuantifiedWhereClauses::from_iter(
|
|
&Interner,
|
|
Some(crate::wrap_empty_binders(WhereClause::Implemented(
|
|
trait_ref,
|
|
))),
|
|
),
|
|
),
|
|
lifetime: static_lifetime(),
|
|
};
|
|
TyKind::Dyn(dyn_ty).intern(&Interner)
|
|
};
|
|
return (ty, None);
|
|
}
|
|
TypeNs::GenericParam(param_id) => {
|
|
let generics = generics(
|
|
self.db.upcast(),
|
|
self.resolver.generic_def().expect("generics in scope"),
|
|
);
|
|
match self.type_param_mode {
|
|
TypeParamLoweringMode::Placeholder => {
|
|
TyKind::Placeholder(to_placeholder_idx(self.db, param_id))
|
|
}
|
|
TypeParamLoweringMode::Variable => {
|
|
let idx = generics.param_idx(param_id).expect("matching generics");
|
|
TyKind::BoundVar(BoundVar::new(self.in_binders, idx))
|
|
}
|
|
}
|
|
.intern(&Interner)
|
|
}
|
|
TypeNs::SelfType(impl_id) => {
|
|
let generics = generics(self.db.upcast(), impl_id.into());
|
|
let substs = match self.type_param_mode {
|
|
TypeParamLoweringMode::Placeholder => generics.type_params_subst(self.db),
|
|
TypeParamLoweringMode::Variable => generics.bound_vars_subst(self.in_binders),
|
|
};
|
|
self.db.impl_self_ty(impl_id).substitute(&Interner, &substs)
|
|
}
|
|
TypeNs::AdtSelfType(adt) => {
|
|
let generics = generics(self.db.upcast(), adt.into());
|
|
let substs = match self.type_param_mode {
|
|
TypeParamLoweringMode::Placeholder => generics.type_params_subst(self.db),
|
|
TypeParamLoweringMode::Variable => generics.bound_vars_subst(self.in_binders),
|
|
};
|
|
self.db.ty(adt.into()).substitute(&Interner, &substs)
|
|
}
|
|
|
|
TypeNs::AdtId(it) => self.lower_path_inner(resolved_segment, it.into(), infer_args),
|
|
TypeNs::BuiltinType(it) => {
|
|
self.lower_path_inner(resolved_segment, it.into(), infer_args)
|
|
}
|
|
TypeNs::TypeAliasId(it) => {
|
|
self.lower_path_inner(resolved_segment, it.into(), infer_args)
|
|
}
|
|
// FIXME: report error
|
|
TypeNs::EnumVariantId(_) => return (TyKind::Error.intern(&Interner), None),
|
|
};
|
|
self.lower_ty_relative_path(ty, Some(resolution), remaining_segments)
|
|
}
|
|
|
|
pub(crate) fn lower_path(&self, path: &Path) -> (Ty, Option<TypeNs>) {
|
|
// Resolve the path (in type namespace)
|
|
if let Some(type_ref) = path.type_anchor() {
|
|
let (ty, res) = self.lower_ty_ext(&type_ref);
|
|
return self.lower_ty_relative_path(ty, res, path.segments());
|
|
}
|
|
let (resolution, remaining_index) =
|
|
match self.resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
|
|
Some(it) => it,
|
|
None => return (TyKind::Error.intern(&Interner), None),
|
|
};
|
|
let (resolved_segment, remaining_segments) = match remaining_index {
|
|
None => (
|
|
path.segments().last().expect("resolved path has at least one element"),
|
|
PathSegments::EMPTY,
|
|
),
|
|
Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
|
|
};
|
|
self.lower_partly_resolved_path(resolution, resolved_segment, remaining_segments, false)
|
|
}
|
|
|
|
fn select_associated_type(&self, res: Option<TypeNs>, segment: PathSegment<'_>) -> Ty {
|
|
if let Some(res) = res {
|
|
let ty = associated_type_shorthand_candidates(
|
|
self.db,
|
|
res,
|
|
move |name, t, associated_ty| {
|
|
if name == segment.name {
|
|
let substs = match self.type_param_mode {
|
|
TypeParamLoweringMode::Placeholder => {
|
|
// if we're lowering to placeholders, we have to put
|
|
// them in now
|
|
let generics = generics(
|
|
self.db.upcast(),
|
|
self.resolver.generic_def().expect(
|
|
"there should be generics if there's a generic param",
|
|
),
|
|
);
|
|
let s = generics.type_params_subst(self.db);
|
|
s.apply(t.substitution.clone(), &Interner)
|
|
}
|
|
TypeParamLoweringMode::Variable => t.substitution.clone(),
|
|
};
|
|
// We need to shift in the bound vars, since
|
|
// associated_type_shorthand_candidates does not do that
|
|
let substs = substs.shifted_in_from(&Interner, self.in_binders);
|
|
// FIXME handle type parameters on the segment
|
|
return Some(
|
|
TyKind::Alias(AliasTy::Projection(ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: substs,
|
|
}))
|
|
.intern(&Interner),
|
|
);
|
|
}
|
|
|
|
None
|
|
},
|
|
);
|
|
|
|
ty.unwrap_or(TyKind::Error.intern(&Interner))
|
|
} else {
|
|
TyKind::Error.intern(&Interner)
|
|
}
|
|
}
|
|
|
|
fn lower_path_inner(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
typeable: TyDefId,
|
|
infer_args: bool,
|
|
) -> Ty {
|
|
let generic_def = match typeable {
|
|
TyDefId::BuiltinType(_) => None,
|
|
TyDefId::AdtId(it) => Some(it.into()),
|
|
TyDefId::TypeAliasId(it) => Some(it.into()),
|
|
};
|
|
let substs = self.substs_from_path_segment(segment, generic_def, infer_args, None);
|
|
self.db.ty(typeable).substitute(&Interner, &substs)
|
|
}
|
|
|
|
/// Collect generic arguments from a path into a `Substs`. See also
|
|
/// `create_substs_for_ast_path` and `def_to_ty` in rustc.
|
|
pub(super) fn substs_from_path(
|
|
&self,
|
|
path: &Path,
|
|
// Note that we don't call `db.value_type(resolved)` here,
|
|
// `ValueTyDefId` is just a convenient way to pass generics and
|
|
// special-case enum variants
|
|
resolved: ValueTyDefId,
|
|
infer_args: bool,
|
|
) -> Substitution {
|
|
let last = path.segments().last().expect("path should have at least one segment");
|
|
let (segment, generic_def) = match resolved {
|
|
ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::StructId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::UnionId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::ConstId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::StaticId(_) => (last, None),
|
|
ValueTyDefId::EnumVariantId(var) => {
|
|
// the generic args for an enum variant may be either specified
|
|
// on the segment referring to the enum, or on the segment
|
|
// referring to the variant. So `Option::<T>::None` and
|
|
// `Option::None::<T>` are both allowed (though the former is
|
|
// preferred). See also `def_ids_for_path_segments` in rustc.
|
|
let len = path.segments().len();
|
|
let penultimate = if len >= 2 { path.segments().get(len - 2) } else { None };
|
|
let segment = match penultimate {
|
|
Some(segment) if segment.args_and_bindings.is_some() => segment,
|
|
_ => last,
|
|
};
|
|
(segment, Some(var.parent.into()))
|
|
}
|
|
};
|
|
self.substs_from_path_segment(segment, generic_def, infer_args, None)
|
|
}
|
|
|
|
fn substs_from_path_segment(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
def_generic: Option<GenericDefId>,
|
|
infer_args: bool,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Substitution {
|
|
let mut substs = Vec::new();
|
|
let def_generics = def_generic.map(|def| generics(self.db.upcast(), def));
|
|
|
|
let (parent_params, self_params, type_params, impl_trait_params) =
|
|
def_generics.map_or((0, 0, 0, 0), |g| g.provenance_split());
|
|
let total_len = parent_params + self_params + type_params + impl_trait_params;
|
|
|
|
substs.extend(iter::repeat(TyKind::Error.intern(&Interner)).take(parent_params));
|
|
|
|
let fill_self_params = || {
|
|
substs.extend(
|
|
explicit_self_ty
|
|
.into_iter()
|
|
.chain(iter::repeat(TyKind::Error.intern(&Interner)))
|
|
.take(self_params),
|
|
)
|
|
};
|
|
let mut had_explicit_type_args = false;
|
|
|
|
if let Some(generic_args) = &segment.args_and_bindings {
|
|
if !generic_args.has_self_type {
|
|
fill_self_params();
|
|
}
|
|
let expected_num =
|
|
if generic_args.has_self_type { self_params + type_params } else { type_params };
|
|
let skip = if generic_args.has_self_type && self_params == 0 { 1 } else { 0 };
|
|
// if args are provided, it should be all of them, but we can't rely on that
|
|
for arg in generic_args
|
|
.args
|
|
.iter()
|
|
.filter(|arg| matches!(arg, GenericArg::Type(_)))
|
|
.skip(skip)
|
|
.take(expected_num)
|
|
{
|
|
match arg {
|
|
GenericArg::Type(type_ref) => {
|
|
had_explicit_type_args = true;
|
|
let ty = self.lower_ty(type_ref);
|
|
substs.push(ty);
|
|
}
|
|
GenericArg::Lifetime(_) => {}
|
|
}
|
|
}
|
|
} else {
|
|
fill_self_params();
|
|
}
|
|
|
|
// handle defaults. In expression or pattern path segments without
|
|
// explicitly specified type arguments, missing type arguments are inferred
|
|
// (i.e. defaults aren't used).
|
|
if !infer_args || had_explicit_type_args {
|
|
if let Some(def_generic) = def_generic {
|
|
let defaults = self.db.generic_defaults(def_generic);
|
|
assert_eq!(total_len, defaults.len());
|
|
|
|
for default_ty in defaults.iter().skip(substs.len()) {
|
|
// each default can depend on the previous parameters
|
|
let substs_so_far = Substitution::from_iter(&Interner, substs.clone());
|
|
substs.push(default_ty.clone().substitute(&Interner, &substs_so_far));
|
|
}
|
|
}
|
|
}
|
|
|
|
// add placeholders for args that were not provided
|
|
// FIXME: emit diagnostics in contexts where this is not allowed
|
|
for _ in substs.len()..total_len {
|
|
substs.push(TyKind::Error.intern(&Interner));
|
|
}
|
|
assert_eq!(substs.len(), total_len);
|
|
|
|
Substitution::from_iter(&Interner, substs)
|
|
}
|
|
|
|
fn lower_trait_ref_from_path(
|
|
&self,
|
|
path: &Path,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Option<TraitRef> {
|
|
let resolved =
|
|
match self.resolver.resolve_path_in_type_ns_fully(self.db.upcast(), path.mod_path())? {
|
|
TypeNs::TraitId(tr) => tr,
|
|
_ => return None,
|
|
};
|
|
let segment = path.segments().last().expect("path should have at least one segment");
|
|
Some(self.lower_trait_ref_from_resolved_path(resolved, segment, explicit_self_ty))
|
|
}
|
|
|
|
pub(crate) fn lower_trait_ref_from_resolved_path(
|
|
&self,
|
|
resolved: TraitId,
|
|
segment: PathSegment<'_>,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> TraitRef {
|
|
let substs = self.trait_ref_substs_from_path(segment, resolved, explicit_self_ty);
|
|
TraitRef { trait_id: to_chalk_trait_id(resolved), substitution: substs }
|
|
}
|
|
|
|
fn lower_trait_ref(
|
|
&self,
|
|
trait_ref: &HirTraitRef,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Option<TraitRef> {
|
|
self.lower_trait_ref_from_path(&trait_ref.path, explicit_self_ty)
|
|
}
|
|
|
|
fn trait_ref_substs_from_path(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
resolved: TraitId,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Substitution {
|
|
self.substs_from_path_segment(segment, Some(resolved.into()), false, explicit_self_ty)
|
|
}
|
|
|
|
pub(crate) fn lower_where_predicate(
|
|
&'a self,
|
|
where_predicate: &'a WherePredicate,
|
|
ignore_bindings: bool,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
match where_predicate {
|
|
WherePredicate::ForLifetime { target, bound, .. }
|
|
| WherePredicate::TypeBound { target, bound } => {
|
|
let self_ty = match target {
|
|
WherePredicateTypeTarget::TypeRef(type_ref) => self.lower_ty(type_ref),
|
|
WherePredicateTypeTarget::TypeParam(param_id) => {
|
|
let generic_def = self.resolver.generic_def().expect("generics in scope");
|
|
let generics = generics(self.db.upcast(), generic_def);
|
|
let param_id =
|
|
hir_def::TypeParamId { parent: generic_def, local_id: *param_id };
|
|
let placeholder = to_placeholder_idx(self.db, param_id);
|
|
match self.type_param_mode {
|
|
TypeParamLoweringMode::Placeholder => TyKind::Placeholder(placeholder),
|
|
TypeParamLoweringMode::Variable => {
|
|
let idx = generics.param_idx(param_id).expect("matching generics");
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, idx))
|
|
}
|
|
}
|
|
.intern(&Interner)
|
|
}
|
|
};
|
|
self.lower_type_bound(bound, self_ty, ignore_bindings)
|
|
.collect::<Vec<_>>()
|
|
.into_iter()
|
|
}
|
|
WherePredicate::Lifetime { .. } => vec![].into_iter(),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_type_bound(
|
|
&'a self,
|
|
bound: &'a TypeBound,
|
|
self_ty: Ty,
|
|
ignore_bindings: bool,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
let mut bindings = None;
|
|
let trait_ref = match bound {
|
|
TypeBound::Path(path) => {
|
|
bindings = self.lower_trait_ref_from_path(path, Some(self_ty));
|
|
bindings.clone().map(WhereClause::Implemented).map(|b| crate::wrap_empty_binders(b))
|
|
}
|
|
TypeBound::Lifetime(_) => None,
|
|
TypeBound::Error => None,
|
|
};
|
|
trait_ref.into_iter().chain(
|
|
bindings
|
|
.into_iter()
|
|
.filter(move |_| !ignore_bindings)
|
|
.flat_map(move |tr| self.assoc_type_bindings_from_type_bound(bound, tr)),
|
|
)
|
|
}
|
|
|
|
fn assoc_type_bindings_from_type_bound(
|
|
&'a self,
|
|
bound: &'a TypeBound,
|
|
trait_ref: TraitRef,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
let last_segment = match bound {
|
|
TypeBound::Path(path) => path.segments().last(),
|
|
TypeBound::Error | TypeBound::Lifetime(_) => None,
|
|
};
|
|
last_segment
|
|
.into_iter()
|
|
.flat_map(|segment| segment.args_and_bindings.into_iter())
|
|
.flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
|
|
.flat_map(move |binding| {
|
|
let found = associated_type_by_name_including_super_traits(
|
|
self.db,
|
|
trait_ref.clone(),
|
|
&binding.name,
|
|
);
|
|
let (super_trait_ref, associated_ty) = match found {
|
|
None => return SmallVec::<[QuantifiedWhereClause; 1]>::new(),
|
|
Some(t) => t,
|
|
};
|
|
let projection_ty = ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: super_trait_ref.substitution,
|
|
};
|
|
let mut preds = SmallVec::with_capacity(
|
|
binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(),
|
|
);
|
|
if let Some(type_ref) = &binding.type_ref {
|
|
let ty = self.lower_ty(type_ref);
|
|
let alias_eq =
|
|
AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };
|
|
preds.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));
|
|
}
|
|
for bound in &binding.bounds {
|
|
preds.extend(self.lower_type_bound(
|
|
bound,
|
|
TyKind::Alias(AliasTy::Projection(projection_ty.clone())).intern(&Interner),
|
|
false,
|
|
));
|
|
}
|
|
preds
|
|
})
|
|
}
|
|
|
|
fn lower_impl_trait(&self, bounds: &[Interned<TypeBound>]) -> ReturnTypeImplTrait {
|
|
cov_mark::hit!(lower_rpit);
|
|
let self_ty =
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(&Interner);
|
|
let predicates = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
|
|
bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)).collect()
|
|
});
|
|
ReturnTypeImplTrait { bounds: crate::make_only_type_binders(1, predicates) }
|
|
}
|
|
}
|
|
|
|
fn count_impl_traits(type_ref: &TypeRef) -> usize {
|
|
let mut count = 0;
|
|
type_ref.walk(&mut |type_ref| {
|
|
if matches!(type_ref, TypeRef::ImplTrait(_)) {
|
|
count += 1;
|
|
}
|
|
});
|
|
count
|
|
}
|
|
|
|
/// Build the signature of a callable item (function, struct or enum variant).
|
|
pub fn callable_item_sig(db: &dyn HirDatabase, def: CallableDefId) -> PolyFnSig {
|
|
match def {
|
|
CallableDefId::FunctionId(f) => fn_sig_for_fn(db, f),
|
|
CallableDefId::StructId(s) => fn_sig_for_struct_constructor(db, s),
|
|
CallableDefId::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
|
|
}
|
|
}
|
|
|
|
pub fn associated_type_shorthand_candidates<R>(
|
|
db: &dyn HirDatabase,
|
|
res: TypeNs,
|
|
mut cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>,
|
|
) -> Option<R> {
|
|
let mut search = |t| {
|
|
for t in all_super_trait_refs(db, t) {
|
|
let data = db.trait_data(t.hir_trait_id());
|
|
|
|
for (name, assoc_id) in &data.items {
|
|
if let AssocItemId::TypeAliasId(alias) = assoc_id {
|
|
if let Some(result) = cb(name, &t, *alias) {
|
|
return Some(result);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
None
|
|
};
|
|
|
|
match res {
|
|
TypeNs::SelfType(impl_id) => search(
|
|
// we're _in_ the impl -- the binders get added back later. Correct,
|
|
// but it would be nice to make this more explicit
|
|
db.impl_trait(impl_id)?.into_value_and_skipped_binders().0,
|
|
),
|
|
TypeNs::GenericParam(param_id) => {
|
|
let predicates = db.generic_predicates_for_param(param_id);
|
|
let res = predicates.iter().find_map(|pred| match pred.skip_binders().skip_binders() {
|
|
// FIXME: how to correctly handle higher-ranked bounds here?
|
|
WhereClause::Implemented(tr) => search(
|
|
tr.clone()
|
|
.shifted_out_to(&Interner, DebruijnIndex::ONE)
|
|
.expect("FIXME unexpected higher-ranked trait bound"),
|
|
),
|
|
_ => None,
|
|
});
|
|
if let res @ Some(_) = res {
|
|
return res;
|
|
}
|
|
// Handle `Self::Type` referring to own associated type in trait definitions
|
|
if let GenericDefId::TraitId(trait_id) = param_id.parent {
|
|
let generics = generics(db.upcast(), trait_id.into());
|
|
if generics.params.types[param_id.local_id].provenance
|
|
== TypeParamProvenance::TraitSelf
|
|
{
|
|
let trait_ref = TyBuilder::trait_ref(db, trait_id)
|
|
.fill_with_bound_vars(DebruijnIndex::INNERMOST, 0)
|
|
.build();
|
|
return search(trait_ref);
|
|
}
|
|
}
|
|
None
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
/// Build the type of all specific fields of a struct or enum variant.
|
|
pub(crate) fn field_types_query(
|
|
db: &dyn HirDatabase,
|
|
variant_id: VariantId,
|
|
) -> Arc<ArenaMap<LocalFieldId, Binders<Ty>>> {
|
|
let var_data = variant_id.variant_data(db.upcast());
|
|
let (resolver, def): (_, GenericDefId) = match variant_id {
|
|
VariantId::StructId(it) => (it.resolver(db.upcast()), it.into()),
|
|
VariantId::UnionId(it) => (it.resolver(db.upcast()), it.into()),
|
|
VariantId::EnumVariantId(it) => (it.parent.resolver(db.upcast()), it.parent.into()),
|
|
};
|
|
let generics = generics(db.upcast(), def);
|
|
let mut res = ArenaMap::default();
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
for (field_id, field_data) in var_data.fields().iter() {
|
|
res.insert(field_id, make_binders(&generics, ctx.lower_ty(&field_data.type_ref)))
|
|
}
|
|
Arc::new(res)
|
|
}
|
|
|
|
/// This query exists only to be used when resolving short-hand associated types
|
|
/// like `T::Item`.
|
|
///
|
|
/// See the analogous query in rustc and its comment:
|
|
/// https://github.com/rust-lang/rust/blob/9150f844e2624eb013ec78ca08c1d416e6644026/src/librustc_typeck/astconv.rs#L46
|
|
/// This is a query mostly to handle cycles somewhat gracefully; e.g. the
|
|
/// following bounds are disallowed: `T: Foo<U::Item>, U: Foo<T::Item>`, but
|
|
/// these are fine: `T: Foo<U::Item>, U: Foo<()>`.
|
|
pub(crate) fn generic_predicates_for_param_query(
|
|
db: &dyn HirDatabase,
|
|
param_id: TypeParamId,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
let resolver = param_id.parent.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let generics = generics(db.upcast(), param_id.parent);
|
|
resolver
|
|
.where_predicates_in_scope()
|
|
// we have to filter out all other predicates *first*, before attempting to lower them
|
|
.filter(|pred| match pred {
|
|
WherePredicate::ForLifetime { target, .. }
|
|
| WherePredicate::TypeBound { target, .. } => match target {
|
|
WherePredicateTypeTarget::TypeRef(type_ref) => {
|
|
ctx.lower_ty_only_param(type_ref) == Some(param_id)
|
|
}
|
|
WherePredicateTypeTarget::TypeParam(local_id) => *local_id == param_id.local_id,
|
|
},
|
|
WherePredicate::Lifetime { .. } => false,
|
|
})
|
|
.flat_map(|pred| ctx.lower_where_predicate(pred, true).map(|p| make_binders(&generics, p)))
|
|
.collect()
|
|
}
|
|
|
|
pub(crate) fn generic_predicates_for_param_recover(
|
|
_db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
_param_id: &TypeParamId,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
Arc::new([])
|
|
}
|
|
|
|
pub(crate) fn trait_environment_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<TraitEnvironment> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx = TyLoweringContext::new(db, &resolver)
|
|
.with_type_param_mode(TypeParamLoweringMode::Placeholder);
|
|
let mut traits_in_scope = Vec::new();
|
|
let mut clauses = Vec::new();
|
|
for pred in resolver.where_predicates_in_scope() {
|
|
for pred in ctx.lower_where_predicate(pred, false) {
|
|
if let WhereClause::Implemented(tr) = &pred.skip_binders() {
|
|
traits_in_scope
|
|
.push((tr.self_type_parameter(&Interner).clone(), tr.hir_trait_id()));
|
|
}
|
|
let program_clause: chalk_ir::ProgramClause<Interner> = pred.clone().cast(&Interner);
|
|
clauses.push(program_clause.into_from_env_clause(&Interner));
|
|
}
|
|
}
|
|
|
|
let container: Option<AssocContainerId> = match def {
|
|
// FIXME: is there a function for this?
|
|
GenericDefId::FunctionId(f) => Some(f.lookup(db.upcast()).container),
|
|
GenericDefId::AdtId(_) => None,
|
|
GenericDefId::TraitId(_) => None,
|
|
GenericDefId::TypeAliasId(t) => Some(t.lookup(db.upcast()).container),
|
|
GenericDefId::ImplId(_) => None,
|
|
GenericDefId::EnumVariantId(_) => None,
|
|
GenericDefId::ConstId(c) => Some(c.lookup(db.upcast()).container),
|
|
};
|
|
if let Some(AssocContainerId::TraitId(trait_id)) = container {
|
|
// add `Self: Trait<T1, T2, ...>` to the environment in trait
|
|
// function default implementations (and speculative code
|
|
// inside consts or type aliases)
|
|
cov_mark::hit!(trait_self_implements_self);
|
|
let substs = TyBuilder::type_params_subst(db, trait_id);
|
|
let trait_ref = TraitRef { trait_id: to_chalk_trait_id(trait_id), substitution: substs };
|
|
let pred = WhereClause::Implemented(trait_ref);
|
|
let program_clause: chalk_ir::ProgramClause<Interner> = pred.cast(&Interner);
|
|
clauses.push(program_clause.into_from_env_clause(&Interner));
|
|
}
|
|
|
|
let krate = def.module(db.upcast()).krate();
|
|
|
|
let env = chalk_ir::Environment::new(&Interner).add_clauses(&Interner, clauses);
|
|
|
|
Arc::new(TraitEnvironment { krate, traits_from_clauses: traits_in_scope, env })
|
|
}
|
|
|
|
/// Resolve the where clause(s) of an item with generics.
|
|
pub(crate) fn generic_predicates_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let generics = generics(db.upcast(), def);
|
|
resolver
|
|
.where_predicates_in_scope()
|
|
.flat_map(|pred| ctx.lower_where_predicate(pred, false).map(|p| make_binders(&generics, p)))
|
|
.collect()
|
|
}
|
|
|
|
/// Resolve the default type params from generics
|
|
pub(crate) fn generic_defaults_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<[Binders<Ty>]> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let generic_params = generics(db.upcast(), def);
|
|
|
|
let defaults = generic_params
|
|
.iter()
|
|
.enumerate()
|
|
.map(|(idx, (_, p))| {
|
|
let mut ty =
|
|
p.default.as_ref().map_or(TyKind::Error.intern(&Interner), |t| ctx.lower_ty(t));
|
|
|
|
// Each default can only refer to previous parameters.
|
|
ty = crate::fold_free_vars(ty, |bound, binders| {
|
|
if bound.index >= idx && bound.debruijn == DebruijnIndex::INNERMOST {
|
|
// type variable default referring to parameter coming
|
|
// after it. This is forbidden (FIXME: report
|
|
// diagnostic)
|
|
TyKind::Error.intern(&Interner)
|
|
} else {
|
|
bound.shifted_in_from(binders).to_ty(&Interner)
|
|
}
|
|
});
|
|
|
|
crate::make_only_type_binders(idx, ty)
|
|
})
|
|
.collect();
|
|
|
|
defaults
|
|
}
|
|
|
|
pub(crate) fn generic_defaults_recover(
|
|
db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
def: &GenericDefId,
|
|
) -> Arc<[Binders<Ty>]> {
|
|
let generic_params = generics(db.upcast(), *def);
|
|
|
|
// we still need one default per parameter
|
|
let defaults = generic_params
|
|
.iter()
|
|
.enumerate()
|
|
.map(|(idx, _)| {
|
|
let ty = TyKind::Error.intern(&Interner);
|
|
|
|
crate::make_only_type_binders(idx, ty)
|
|
})
|
|
.collect();
|
|
|
|
defaults
|
|
}
|
|
|
|
fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
|
|
let data = db.function_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx_params = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Variable)
|
|
.with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let params = data.params.iter().map(|tr| ctx_params.lower_ty(tr)).collect::<Vec<_>>();
|
|
let ctx_ret = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
|
|
.with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let ret = ctx_ret.lower_ty(&data.ret_type);
|
|
let generics = generics(db.upcast(), def.into());
|
|
make_binders(&generics, CallableSig::from_params_and_return(params, ret, data.is_varargs()))
|
|
}
|
|
|
|
/// Build the declared type of a function. This should not need to look at the
|
|
/// function body.
|
|
fn type_for_fn(db: &dyn HirDatabase, def: FunctionId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), def.into());
|
|
let substs = generics.bound_vars_subst(DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::FunctionId(def).to_chalk(db), substs).intern(&Interner),
|
|
)
|
|
}
|
|
|
|
/// Build the declared type of a const.
|
|
fn type_for_const(db: &dyn HirDatabase, def: ConstId) -> Binders<Ty> {
|
|
let data = db.const_data(def);
|
|
let generics = generics(db.upcast(), def.into());
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
|
|
make_binders(&generics, ctx.lower_ty(&data.type_ref))
|
|
}
|
|
|
|
/// Build the declared type of a static.
|
|
fn type_for_static(db: &dyn HirDatabase, def: StaticId) -> Binders<Ty> {
|
|
let data = db.static_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx = TyLoweringContext::new(db, &resolver);
|
|
|
|
Binders::empty(&Interner, ctx.lower_ty(&data.type_ref))
|
|
}
|
|
|
|
fn fn_sig_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> PolyFnSig {
|
|
let struct_data = db.struct_data(def);
|
|
let fields = struct_data.variant_data.fields();
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let params = fields.iter().map(|(_, field)| ctx.lower_ty(&field.type_ref)).collect::<Vec<_>>();
|
|
let (ret, binders) = type_for_adt(db, def.into()).into_value_and_skipped_binders();
|
|
Binders::new(binders, CallableSig::from_params_and_return(params, ret, false))
|
|
}
|
|
|
|
/// Build the type of a tuple struct constructor.
|
|
fn type_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> Binders<Ty> {
|
|
let struct_data = db.struct_data(def);
|
|
if let StructKind::Unit = struct_data.variant_data.kind() {
|
|
return type_for_adt(db, def.into());
|
|
}
|
|
let generics = generics(db.upcast(), def.into());
|
|
let substs = generics.bound_vars_subst(DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::StructId(def).to_chalk(db), substs).intern(&Interner),
|
|
)
|
|
}
|
|
|
|
fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> PolyFnSig {
|
|
let enum_data = db.enum_data(def.parent);
|
|
let var_data = &enum_data.variants[def.local_id];
|
|
let fields = var_data.variant_data.fields();
|
|
let resolver = def.parent.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let params = fields.iter().map(|(_, field)| ctx.lower_ty(&field.type_ref)).collect::<Vec<_>>();
|
|
let (ret, binders) = type_for_adt(db, def.parent.into()).into_value_and_skipped_binders();
|
|
Binders::new(binders, CallableSig::from_params_and_return(params, ret, false))
|
|
}
|
|
|
|
/// Build the type of a tuple enum variant constructor.
|
|
fn type_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> Binders<Ty> {
|
|
let enum_data = db.enum_data(def.parent);
|
|
let var_data = &enum_data.variants[def.local_id].variant_data;
|
|
if let StructKind::Unit = var_data.kind() {
|
|
return type_for_adt(db, def.parent.into());
|
|
}
|
|
let generics = generics(db.upcast(), def.parent.into());
|
|
let substs = generics.bound_vars_subst(DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::EnumVariantId(def).to_chalk(db), substs).intern(&Interner),
|
|
)
|
|
}
|
|
|
|
fn type_for_adt(db: &dyn HirDatabase, adt: AdtId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), adt.into());
|
|
let b = TyBuilder::adt(db, adt);
|
|
let ty = b.fill_with_bound_vars(DebruijnIndex::INNERMOST, 0).build();
|
|
make_binders(&generics, ty)
|
|
}
|
|
|
|
fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), t.into());
|
|
let resolver = t.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
if db.type_alias_data(t).is_extern {
|
|
Binders::empty(&Interner, TyKind::Foreign(crate::to_foreign_def_id(t)).intern(&Interner))
|
|
} else {
|
|
let type_ref = &db.type_alias_data(t).type_ref;
|
|
let inner = ctx.lower_ty(type_ref.as_deref().unwrap_or(&TypeRef::Error));
|
|
make_binders(&generics, inner)
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
|
|
pub enum CallableDefId {
|
|
FunctionId(FunctionId),
|
|
StructId(StructId),
|
|
EnumVariantId(EnumVariantId),
|
|
}
|
|
impl_from!(FunctionId, StructId, EnumVariantId for CallableDefId);
|
|
|
|
impl CallableDefId {
|
|
pub fn krate(self, db: &dyn HirDatabase) -> CrateId {
|
|
let db = db.upcast();
|
|
match self {
|
|
CallableDefId::FunctionId(f) => f.lookup(db).module(db),
|
|
CallableDefId::StructId(s) => s.lookup(db).container,
|
|
CallableDefId::EnumVariantId(e) => e.parent.lookup(db).container,
|
|
}
|
|
.krate()
|
|
}
|
|
}
|
|
|
|
impl From<CallableDefId> for GenericDefId {
|
|
fn from(def: CallableDefId) -> GenericDefId {
|
|
match def {
|
|
CallableDefId::FunctionId(f) => f.into(),
|
|
CallableDefId::StructId(s) => s.into(),
|
|
CallableDefId::EnumVariantId(e) => e.into(),
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
|
|
pub enum TyDefId {
|
|
BuiltinType(BuiltinType),
|
|
AdtId(AdtId),
|
|
TypeAliasId(TypeAliasId),
|
|
}
|
|
impl_from!(BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId for TyDefId);
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
|
|
pub enum ValueTyDefId {
|
|
FunctionId(FunctionId),
|
|
StructId(StructId),
|
|
UnionId(UnionId),
|
|
EnumVariantId(EnumVariantId),
|
|
ConstId(ConstId),
|
|
StaticId(StaticId),
|
|
}
|
|
impl_from!(FunctionId, StructId, UnionId, EnumVariantId, ConstId, StaticId for ValueTyDefId);
|
|
|
|
/// Build the declared type of an item. This depends on the namespace; e.g. for
|
|
/// `struct Foo(usize)`, we have two types: The type of the struct itself, and
|
|
/// the constructor function `(usize) -> Foo` which lives in the values
|
|
/// namespace.
|
|
pub(crate) fn ty_query(db: &dyn HirDatabase, def: TyDefId) -> Binders<Ty> {
|
|
match def {
|
|
TyDefId::BuiltinType(it) => Binders::empty(&Interner, TyBuilder::builtin(it)),
|
|
TyDefId::AdtId(it) => type_for_adt(db, it),
|
|
TyDefId::TypeAliasId(it) => type_for_type_alias(db, it),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn ty_recover(db: &dyn HirDatabase, _cycle: &[String], def: &TyDefId) -> Binders<Ty> {
|
|
let generics = match *def {
|
|
TyDefId::BuiltinType(_) => {
|
|
return Binders::empty(&Interner, TyKind::Error.intern(&Interner))
|
|
}
|
|
TyDefId::AdtId(it) => generics(db.upcast(), it.into()),
|
|
TyDefId::TypeAliasId(it) => generics(db.upcast(), it.into()),
|
|
};
|
|
make_binders(&generics, TyKind::Error.intern(&Interner))
|
|
}
|
|
|
|
pub(crate) fn value_ty_query(db: &dyn HirDatabase, def: ValueTyDefId) -> Binders<Ty> {
|
|
match def {
|
|
ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
|
|
ValueTyDefId::StructId(it) => type_for_struct_constructor(db, it),
|
|
ValueTyDefId::UnionId(it) => type_for_adt(db, it.into()),
|
|
ValueTyDefId::EnumVariantId(it) => type_for_enum_variant_constructor(db, it),
|
|
ValueTyDefId::ConstId(it) => type_for_const(db, it),
|
|
ValueTyDefId::StaticId(it) => type_for_static(db, it),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn impl_self_ty_query(db: &dyn HirDatabase, impl_id: ImplId) -> Binders<Ty> {
|
|
let impl_data = db.impl_data(impl_id);
|
|
let resolver = impl_id.resolver(db.upcast());
|
|
let generics = generics(db.upcast(), impl_id.into());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
make_binders(&generics, ctx.lower_ty(&impl_data.self_ty))
|
|
}
|
|
|
|
pub(crate) fn const_param_ty_query(db: &dyn HirDatabase, def: ConstParamId) -> Ty {
|
|
let parent_data = db.generic_params(def.parent);
|
|
let data = &parent_data.consts[def.local_id];
|
|
let resolver = def.parent.resolver(db.upcast());
|
|
let ctx = TyLoweringContext::new(db, &resolver);
|
|
|
|
ctx.lower_ty(&data.ty)
|
|
}
|
|
|
|
pub(crate) fn impl_self_ty_recover(
|
|
db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
impl_id: &ImplId,
|
|
) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), (*impl_id).into());
|
|
make_binders(&generics, TyKind::Error.intern(&Interner))
|
|
}
|
|
|
|
pub(crate) fn impl_trait_query(db: &dyn HirDatabase, impl_id: ImplId) -> Option<Binders<TraitRef>> {
|
|
let impl_data = db.impl_data(impl_id);
|
|
let resolver = impl_id.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let (self_ty, binders) = db.impl_self_ty(impl_id).into_value_and_skipped_binders();
|
|
let target_trait = impl_data.target_trait.as_ref()?;
|
|
Some(Binders::new(binders, ctx.lower_trait_ref(target_trait, Some(self_ty))?))
|
|
}
|
|
|
|
pub(crate) fn return_type_impl_traits(
|
|
db: &dyn HirDatabase,
|
|
def: hir_def::FunctionId,
|
|
) -> Option<Arc<Binders<ReturnTypeImplTraits>>> {
|
|
// FIXME unify with fn_sig_for_fn instead of doing lowering twice, maybe
|
|
let data = db.function_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx_ret = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
|
|
.with_type_param_mode(TypeParamLoweringMode::Variable);
|
|
let _ret = (&ctx_ret).lower_ty(&data.ret_type);
|
|
let generics = generics(db.upcast(), def.into());
|
|
let return_type_impl_traits =
|
|
ReturnTypeImplTraits { impl_traits: ctx_ret.opaque_type_data.into_inner() };
|
|
if return_type_impl_traits.impl_traits.is_empty() {
|
|
None
|
|
} else {
|
|
Some(Arc::new(make_binders(&generics, return_type_impl_traits)))
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mutability {
|
|
match m {
|
|
hir_def::type_ref::Mutability::Shared => Mutability::Not,
|
|
hir_def::type_ref::Mutability::Mut => Mutability::Mut,
|
|
}
|
|
}
|
|
|
|
fn make_binders<T: HasInterner<Interner = Interner>>(generics: &Generics, value: T) -> Binders<T> {
|
|
crate::make_only_type_binders(generics.len(), value)
|
|
}
|